Various types of sheet feeding apparatus to provide sheets to printing machines are known, in which the sheets are placed on a stack which is height-adjustable, so that the sheets are then peeled off and transported to a make-ready table. One sheet supply apparatus of this type is described, for example, in German Published Patent Application No. DE-AS 17 86 545.
If it is desired to save paper and not effect initial run-through of printing runs on high-quality paper, it was heretofore necessary to place a stack of secondary or waste or scrap paper manually on the stack which contained the good, high-quality paper. It is frequently desirable to save such high-quality paper and replace these sheets of paper by scrap when, for example, a stoppage occurred in the printing run and the subsequent run-on of the machine might produce further scrap.